Latest VISI from Hexagon improves progressive die design

The latest release (2020.1) of VISI mould and die software from Hexagon Production Software enhances the progressive die design processes, along with enhancements for the ‘Reverse’ module.

Among the many improvements, new part unfolding technology now provides the ability to work directly on the original solid model, support blanking functionality and manage parts with non-linear bends.

Furthermore, sheet-metal part recognition now provides an improved graphical representation of the component, analysed by identifying bends, planar faces and features. Different face types can be set, to be considered for the blanking process. The newly-developed technology allows linear blank unfolding and flange unfolding to be combined in a single function. With linear bends, the system will unfold using the linear bend unfolding technology, while flange areas unfold using the FEA solution. Coining faces can also be unfolded as part of the same process.

VISI product manager Marco Cafasso says the major advantage of the technology is the associativity provided with the original model during the die design process.

“It allows the original part to be modified, and changes to be automatically propagated on the banked part,” he explains. “The feature permits all the linked parts to be rebuilt in reference to a modification performed on the original part. This is useful because it updates all the studied parts in a single click, and is a major time saver in the design and modification phase of a progressive die.”

VISI 2020.1 also provides a direct interface to Stampack Xpress, for die simulation.

Additionally, the ‘Reverse’ module has been enhanced with more functions for both reverse and casting processes.

Cafasso says features such as radius generation from mesh, plane generation, adapt mesh on boundary, and sectional curves on mesh, provide greater benefits for the reverse process, from point scanning to solid-model generation.

“A newly introduced ‘Best Fit’ feature aligns a stock model to the final solid model by setting tolerances on different faces,” he reports. “This is useful for the casting market as it allows the cast model to be scanned, achieving a best fit alignment with the final geometry, producing an optimised tool path with reduced machining time. Stock models can then also be used for machining simulation purposes.”

Importantly, the ‘Compare’ feature has been improved to provide enhanced graphical evaluation of the results, and to display distances between the scanned model and final solid model. These enhancements provide quality improvements to both processes, as well as time savings.

In terms of mould-tool design, body-to-mould functionality has been introduced that provides a quick solution to define the correct position and orientation of a plastic part on the tool. This feature allows the transformation of the model from the ‘car in line’ position to the mould position, and to apply the required shrinkage value.

“Creating CAM operations on any arbitrary part geometry is relatively easy nowadays, as components can be virtually designed, created and produced,” says Cafasso. “However, once CAM is finished there is one last operation that is not yet automated, and is usually done manually after machining. Burrs occur on all components that have straight edges or non-tangent outer surface topologies. It’s an unwanted situation because it can destroy the functionality of the part and can even be a danger to the worker as it is razor sharp. So, most of the time it’s essential to remove it.”

The purpose of VISI’s deburring strategy is to provide automatic finishing to the machined part’s sharp edges – an important phase of the manufacturing process for parts with no tangent surfaces. This function creates an automated tool path to deburr the sharp edge of a workpiece with a spherical tool. The tool is positioned in the bi-vector of the automatically detected sharp edges. Automatic tilting and linking is then applied to avoid collisions.

In addition, the 5-axis ‘Autotilting’ capability has been enhanced in VISI 2020.1, with newly added smoothing options based on a more sophisticated interpolation algorithm. This update optimises the contour while keeping the tilt angles in a limited range, resulting in more fluent movement of the machine when milling.

Finally, newly devised graphical representations assist in validating the model for manufacturing purposes.